1. Field of the Invention
The present invention relates to an ink-jet recording apparatus, which forms an image by ejecting ink from a recording head onto a medium to be recorded.
2. Brief Description of the Related Art
In a recording apparatus (printer) where ink is ejected from ink eject nozzles (eject ports, eject portion) and is deposited onto a facing recording medium, the following phenomena, which result in poor printing quality, some times happen. (1) Generated bubbles are gradually accumulating in ink nozzles as a print operating time elapses. (2) Inks in nozzles are thickened as a print operating time elapses. In order to eliminate these phenomena, a method where ink is forcibly sucked for recovering, is employed for enabling printing operations. Since a large amount of ink is discharged in sucking recovery operations, sucking frequency should be kept as few as possible so as to suppress wasted volume of ink. For that purpose, timers are arranged in conventional printer apparatuses so that elapsed times after sucking operations are executed are measured and timings for sucking operations are decide according to the measured elapsed time. Recently, pigments have been being used in place of conventionally used dyes as coloring materials for black inks in order to improve quality of the black color.
However, even in the case of the above-mentioned example where inks with different properties, i.e. a pigment as the black color material and dyes as other color materials are employed, threshold times set by timers for controlling sucking operations are equal in black and color inks, though the black ink made from the pigment tends to be stuck and thickened compared with color inks made from dyes. Consequently, since threshold times are set according to properties of the black color, which apt to be thickened, sometimes color inks are sucked before sucking recovery operations are required, as a result, color inks are wasted.
The present invention is carried out in view of the above-mentioned problems and the objective of the present invention is to provide an ink-jet recording apparatus capable of reducing wasted ink and at the same time suppressing a frequency of recovery treatments.
(1) An ink-jet recording apparatus comprising: a recovery means for executing recovery treatment respectively for a first eject port for ejecting first ink and a second eject port for ejecting second ink different from the first ink; and a control means for causing the recovery means to execute recovery treatment for the first eject port and/or the second eject port which corresponding elapsed time after the recovery means executes a most recent recovery treatment exceeds respective predetermined threshold times peculiar to the respective first eject port and second eject port, where: the predetermined threshold time for the first eject port is set at nearly natural number times as long as the predetermined threshold time for the second eject port, the natural number being two or more.
(2) The ink-jet recording apparatus according to (1), where: the first eject port is provide to a color head unit for ejecting color ink as the first ink; and the second eject port is provided to a black unit head for ejecting black ink as the second ink.
(3) The ink-jet recording apparatus according to (1), where: the first ink includes dye as coloring material; and the second ink includes pigment as coloring material.
(4) The ink-jet recording apparatus according to (1), where: the recovery means executes recovery treatment when data for recording is received.
(5) The ink-jet recording apparatus according to (1), where: electro-thermal converting bodies for generating thermal energy to be utilized to eject ink are arranged corresponding to the respective first eject port and second eject port.
(6) An ink-jet recording apparatus comprising: a recovery means for executing recovery treatment respectively for a first eject port for ejecting first ink and a second eject port for ejecting second ink different from the first ink; and a measuring means for measuring elapsed time after the recovery means executes a most recent recovery treatment for the respective first eject port and second eject port; and a control means for causing the recovery means to execute recovery treatment for the first eject port and/or the second eject port which corresponding elapsed time measured by the measuring means exceeds respective predetermined threshold times peculiar to the respective first eject port and second eject port, and for clearing the elapsed time measured by the measuring means which corresponding eject port is recovered by the recovery means, where: the predetermined threshold time for the first eject port is set at nearly natural number times as long as the predetermined threshold time for the second eject port, the natural number being two or more.
(7) An ink-jet recording apparatus according to (6), where: the first eject ports is provided to a color head unit for ejecting color ink as the first ink and the second eject port is provided to a black head unit for ejecting black ink as the second ink.
(8) The ink-jet recording apparatus according to (6), where: the first ink includes dye as coloring material; and the second ink includes pigment as coloring material.
(9) The ink-jet recording apparatus according to (6), where: the recovery means executes recovery treatment when data for recording is received.
(10) An ink-jet recording apparatus according to (6), where: electro-thermal converting bodies for generating thermal energy to be utilized to eject ink are arranged correponding to the respective first eject port and second eject port.